From 90c464e1a4c06abd1c48720ca063b456cee10838 Mon Sep 17 00:00:00 2001
From: chrchr-github <78114321+chrchr-github@users.noreply.github.com>
Date: Tue, 28 Jan 2025 23:03:13 +0100
Subject: [PATCH] Fix #13593 Template not simplified with global scope operator
 (#7267)

---
 .selfcheck_suppressions       |  4 +++-
 lib/templatesimplifier.cpp    | 17 ++++++++++++++---
 test/testsimplifytemplate.cpp | 17 +++++++++++++++++
 3 files changed, 34 insertions(+), 4 deletions(-)

diff --git a/.selfcheck_suppressions b/.selfcheck_suppressions
index cec87cd9c47..ec4db9fa7e1 100644
--- a/.selfcheck_suppressions
+++ b/.selfcheck_suppressions
@@ -16,6 +16,8 @@ functionStatic:*/ui_fileview.h
 valueFlowBailout
 valueFlowBailoutIncompleteVar
 autoNoType
+# ticket 11631
+templateInstantiation:test/testutils.cpp
 
 naming-varname:externals/simplecpp/simplecpp.h
 naming-privateMemberVariable:externals/simplecpp/simplecpp.h
@@ -32,4 +34,4 @@ functionStatic:externals/tinyxml2/tinyxml2.h
 invalidPrintfArgType_uint:externals/tinyxml2/tinyxml2.cpp
 funcArgNamesDifferent:externals/tinyxml2/tinyxml2.cpp
 nullPointerRedundantCheck:externals/tinyxml2/tinyxml2.cpp
-knownConditionTrueFalse:externals/tinyxml2/tinyxml2.cpp
\ No newline at end of file
+knownConditionTrueFalse:externals/tinyxml2/tinyxml2.cpp
diff --git a/lib/templatesimplifier.cpp b/lib/templatesimplifier.cpp
index 59987a68b7c..c48217928ed 100644
--- a/lib/templatesimplifier.cpp
+++ b/lib/templatesimplifier.cpp
@@ -774,6 +774,19 @@ static bool areAllParamsTypes(const std::vector<const Token *> &params)
     });
 }
 
+static bool isTemplateInstantion(const Token* tok)
+{
+    if (!tok->isName() || (tok->isKeyword() && !tok->isOperatorKeyword()))
+        return false;
+    if (Token::Match(tok->tokAt(-1), "%type% %name% ::|<"))
+        return true;
+    if (Token::Match(tok->tokAt(-2), "[,:] private|protected|public %name% ::|<"))
+        return true;
+    if (Token::Match(tok->tokAt(-1), "(|{|}|;|=|>|<<|:|.|*|&|return|<|,|!|[ %name% ::|<|("))
+        return true;
+    return Token::Match(tok->tokAt(-2), "(|{|}|;|=|<<|:|.|*|&|return|<|,|!|[ :: %name% ::|<|(");
+}
+
 void TemplateSimplifier::getTemplateInstantiations()
 {
     std::multimap<std::string, const TokenAndName *> functionNameMap;
@@ -830,9 +843,7 @@ void TemplateSimplifier::getTemplateInstantiations()
             Token *tok2 = Token::findsimplematch(tok->tokAt(2), ";");
             if (tok2)
                 tok = tok2;
-        } else if (Token::Match(tok->previous(), "(|{|}|;|=|>|<<|:|.|*|&|return|<|,|!|[ %name% ::|<|(") ||
-                   Token::Match(tok->previous(), "%type% %name% ::|<") ||
-                   Token::Match(tok->tokAt(-2), "[,:] private|protected|public %name% ::|<")) {
+        } else if (isTemplateInstantion(tok)) {
             if (!tok->scopeInfo())
                 syntaxError(tok);
             std::string scopeName = tok->scopeInfo()->name;
diff --git a/test/testsimplifytemplate.cpp b/test/testsimplifytemplate.cpp
index a25e11b9304..21be4f834e1 100644
--- a/test/testsimplifytemplate.cpp
+++ b/test/testsimplifytemplate.cpp
@@ -241,6 +241,7 @@ class TestSimplifyTemplate : public TestFixture {
         TEST_CASE(template_namespace_10);
         TEST_CASE(template_namespace_11); // #7145
         TEST_CASE(template_namespace_12);
+        TEST_CASE(template_namespace_13);
         TEST_CASE(template_pointer_type);
         TEST_CASE(template_array_type);
 
@@ -5313,6 +5314,22 @@ class TestSimplifyTemplate : public TestFixture {
                       tok(code));
     }
 
+    void template_namespace_13() {
+        const char code[] = "namespace N {\n" // #13593
+                            "    template<typename T>\n"
+                            "    struct S {\n"
+                            "        using U = T*;\n"
+                            "    };\n"
+                            "}\n"
+                            "::N::S<int>::U u;\n";
+        ASSERT_EQUALS("namespace N { "
+                      "struct S<int> ; "
+                      "} "
+                      "int * u ; "
+                      "struct N :: S<int> { } ;",
+                      tok(code));
+    }
+
     void template_pointer_type() {
         const char code[] = "template<class T> void foo(const T x) {}\n"
                             "void bar() { foo<int*>(0); }";